Optimizing Retention in a Pragmatic Trial of Community-Living Older Persons: The STRIDE Study

OBJECTIVES The Strategies to Reduce Injuries and Develop Confidence in Elders (STRIDE) study is testing the effectiveness of a multifactorial intervention to prevent serious fall injuries. Our aim was to describe procedures that were implemented to optimize participant retention; report retention yields by age, sex, clinical site, and follow-up time; provide reasons for study withdrawals; and highlight the successes and lessons learned from the STRIDE retention efforts. DESIGN Pragmatic cluster randomized trial. SETTING A total of 86 primary care practices within 10 US healthcare systems. PARTICIPANTS A total of 5451 community-living persons, 70 years of age or older, at high risk for serious fall injuries. MEASUREMENTS Study outcomes were collected every 4 months by a central call center. Reconsent was required to extend follow-up beyond the originally planned 36 months. RESULTS Over a median follow-up of 3.2 years (interquartile range = 2.8-3.7 y), 439 (8.1%) participants died and 600 (11.0%) withdrew their consent or did not reconsent to extend follow-up beyond 36 months, yielding rates (per 100 person-years) of deaths and withdrawals of 2.6 and 3.6, respectively. The withdrawal rate increased with advancing age, was comparable for men and women, and did not differ much by clinical site. The most common reasons for withdrawal were illness and unable to contact for reconsent at 36 months. Completion of the follow-up interviews was greater than 93% at each time point. Most participants completed all (71.8%) or all but one (9.2%) of the follow-up interviews. The most common reason for not completing a follow-up interview was unable to contact, with rates ranging from 2.8% at 40 months to 4.6% at 20 months. CONCLUSION Completion of the thrice-yearly follow-up interviews in STRIDE was high, and retention of participants over 44 months exceeded the original projections. The procedures used in STRIDE, together with lessons learned, should assist other investigators who are planning or conducting large pragmatic trials of vulnerable older persons.